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Bunch-length measurement at a bunch-by-bunch rate based on time–frequency-domain joint analysis techniques and its application

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Nuclear Science and Techniques 2024年第4期35卷 165-175页

作者： Hong-Shuang wang Xing Yang yong-Bin Leng Yi-Mei Zhou Ji-Gang wang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage *** technique uses the time–frequency-domain joint analysis of the bunch signal to obtain bunch-by-bunch and turn-by-turn longitudinal parameters,such as bunch length and synchronous *** bunch signal is obtained using a button electrode with a bandwidth of several *** data acquisition device was a high-speed digital oscilloscope with a sampling rate of more than 10 GS/s,and the single-shot sampling data buffer covered thousands of *** bunch-length and synchronous phase information were extracted via offline calculations using Python *** calibration coefficient of the system was determined using a commercial streak ***,this technique was tested on two different storage rings and successfully captured various longitudinal transient processes during the harmonic cavity debugging process at the Shanghai Synchrotron Radiation Facility(SSRF),and longitudinal instabilities were observed during the single-bunch accumulation process at Hefei Light Source(HLS).For Gaussian-distribution bunches,the uncertainty of the bunch phase obtained using this technique was better than 0.2 ps,and the bunch-length uncertainty was better than 1 *** dynamic range exceeded 10 *** technology is a powerful and versatile beam diagnostic tool that can be conveniently deployed in high-energy electron storage rings.

关键词： Bunch-by-bunch diagnostic Bunch-length measurement Synchronous phase measurement Joint time–frequency-domain analysis Longitudinal instability

Unlocking the potential of ultra-thin two-dimensional antimony materials:Selective growth and carbon coating for efficient potassium-ion storage

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Journal of Energy Chemistry 2024年第5期92卷 440-449页

作者： Dongyu Zhang Zhaomin wang Yabin Shen Yeguo Zou Chunli wang Limin wang yong Cheng State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences(CAS)Changchun 130022JilinChina School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina

Antimony-based anodes have attracted wide attention in potassium-ion batteries due to their high theoretical specific capacities(∼660 mA h g^(-1))and suitable voltage ***,severe capacity fading caused by huge volume change and limited ion transportation hinders their practical ***,strategies for controlling the morphologies of Sb-based materials to improve the electrochemical performances have been *** these,the two-dimensional Sb(2D-Sb)materials present excellent properties due to shorted ion immigration paths and enhanced ion ***,the synthetic methods are usually tedious,and even the mechanism of these strategies remains elusive,especially how to obtain large-scale 2D-Sb ***,a novel strategy to synthesize 2D-Sb material using a straightforward solvothermal method without the requirement of a complex nanostructure design is *** method leverages the selective adsorption of aldehyde groups in furfural to induce crystal growth,while concurrently reducing and coating a nitrogen-doped carbon *** to the reported methods,it is simpler,more efficient,and conducive to the production of composite nanosheets with uniform thickness(3–4 nm).The 2D-Sb@NC nanosheet anode delivers an extremely high capacity of 504.5 mA h g^(-1) at current densities of 100 mA g^(-1) and remains stable for more than 200 *** characterizations and molecular dynamic simulations,how potassium storage kinetics between 2D Sb-based materials and bulk Sb-based materials are explored,and detailed explanations are *** findings offer novel insights into the development of durable 2D alloy-based anodes for next-generation potassium-ion batteries.

关键词： Antimony Two-dimensional materials Selective growth Nitrogen-doped carbon Potassium-ion batteries

Fracture behavior and mechanism of highly fragmented steel cylindrical shell under explosive loading

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Defence Technology（防务技术） 2024年第6期36卷 122-132页

作者： Kang wang Peng Chen Xingyun Sun Yufeng Liu Jiayu Meng Xiaoyuan Li Xiongwei Zheng chuan Xiao Xi'an Modern Chemistry Research Institute Xi'an 710065China Shanxi Jiangyang Chemical Company Limited Taiyuan 030051China Central Iron&Steel Research Institute Company Limited Beijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

An in-depth understanding of the fracture behavior and mechanism of metallic shells under internal explosive loading can help develop material designs for warheads and regulate the quantity and mass distribution of the fragments *** study investigated the fragmentation performance of a new high-carbon silicon-manganese(HCSiMn)steel cylindrical shell through fragment recovery *** with the conventional 45Cr steel shell,the number of small mass fragments produced by the HCSi Mn steel shell was significantly increased with a scale parameter of 0.57 g fitted by the Weibull distribution *** fragmentation process of the HCSi Mn shell exhibited more brittle tensile fracture characteristics,with the microcrack damage zone on the outer surface being the direct cause of its high *** the one hand,the doping of alloy elements resulted in grain refinement by forming metallographic structure of tempered sorbite,so that microscopic intergranular fracture reduces the characteristic mass of the fragments;on the other hand,the distribution of alloy carbides can exert a"pinning"effect on the substrate grains,causing more initial cracks to form and propagate along the brittle carbides,further improving the shell *** the killing power radius for light armored vehicles was slightly reduced by about 6%,the dense killing radius of HCSiMn steel projectile against personnel can be significantly increased by about 26%based on theoretical *** results provided an experimental basis for high fragmentation warhead design,and to some extent,revealed the correlation mechanism between metallographic structure and shell fragmentation.

关键词： Projectile fragmentation Fragment mass distribution Fracture mode Metallographic structure Damage power

Preoperative prediction of perineural invasion of rectal cancer based on a magnetic resonance imaging radiomics model:A dual-center study

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World Journal of Gastroenterology 2024年第16期30卷 2233-2248页

作者： Yan Liu Bai-Jin-Tao Sun chuan Zhang Bing Li Xiao-Xuan Yu yong Du Department of Radiology The Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina Department of Radiology The Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina.duyong@***

BACKGROUND Perineural invasion(PNI)has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer(RC).Preoperative prediction of PNI status is helpful for individualized treatment of ***,several radiomics studies have been used to predict the PNI status in RC,demonstrating a good predictive effect,but the results lacked *** preoperative prediction of PNI status is still challenging and needs further *** To establish and validate an optimal radiomics model for predicting PNI status preoperatively in RC *** This retrospective study enrolled 244 postoperative patients with pathologically confirmed RC from two independent *** patients underwent preoperative high-resolution magnetic resonance imaging(MRI)between May 2019 and August *** radiomics features were extracted and selected from oblique axial T2-weighted imaging(T2WI)and contrast-enhanced T1WI(T1CE)*** radiomics signatures were constructed using logistic regression analysis and the predictive potential of various sequences was compared(T2WI,T1CE and T2WI+T1CE fusion sequences).A clinical-radiomics(CR)model was established by combining the radiomics features and clinical risk *** internal and external validation groups were used to validate the proposed *** area under the receiver operating characteristic curve(AUC),DeLong test,net reclassification improvement(NRI),integrated discrimination improvement(IDI),calibration curve,and decision curve analysis(DCA)were used to evaluate the model *** Among the radiomics models,the T2WI+T1CE fusion sequences model showed the best predictive performance,in the training and internal validation groups,the AUCs of the fusion sequence model were 0.839[95%confidence interval(CI):0.757-0.921]and 0.787(95%CI:0.650-0.923),which were higher than those of the T2WI and T1CE sequence *** CR model constructed by combinin

关键词： Rectal cancer Perineural invasion Magnetic resonance imaging Radiomics Nomogram

Experimental study on wax deposition of highly paraffinic oil in intermittent gas-oil flow in pipelines

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Petroleum Science 2024年第3期21卷 2080-2088页

作者： chuan-Shuo wang Qian-Li Ma Xiao-Fang Lv Jie Zhang Yang Liu Shi-Dong Zhou Jiangsu Key Laboratory of Oil and Gas Storage and Transportation Technology Changzhou UniversityChangzhou213164JiangsuPR China Hade Oil and Gas Development Department Tarim Oilfield BranchKorla841000XinjiangPR China

Oil-gas two phase wax deposition is a fairly common and open-ended question in flow assurance of multiphase transportation *** paper investigated the two main aspects of oil-gas two phase wax deposition layer:apparent thickness and crystal structure characteristics.A typical highly paraffinic oil in Bohai Sea,China,was used as the experimental material to investigate the wax deposition thickness in oil-gas two phase under the influence of different oil temperatures,superficial gas/liquid phase velocities and gas-oil ratios by using multiphase flow loop experimental *** as in the classical theory of wax molecular diffusion,it showed that wax deposition thickness of oil-gas two phase increased with increasing oil *** of the impact of different superficial phase velocities found that the actual liquid flow heat transfer and shear stripping was the gas phase dominant mechanisms determining wax deposit *** addition,the crystal structure of the wax deposition layer was characterized with the help of small-angle X-ray scattering(SAXS)for different circumferential positions,flow rates and gas-oil *** bottom deposition layer had a complex crystal structure and high hardness,which were subject to change over flow rate ***,the SAXS results provided evidence that the indirect effect of the actual liquid velocity modified by the gas phase was the main *** study of the effect of gas phase on the wax deposition of oil-gas two phase will help shed light onto the mechanism by which this important process *** findings address a very urgent need in the field of wax deposition of highly paraffinic oil to understand the flow security of oilgas two phase that occurs easily in multiphase field pipelines.

关键词： Oil-gas two phase Highly paraffinic oil Wax deposition SAXS

Distributed Graph Database Load Balancing Method Based on Deep Reinforcement Learning

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Computers, Materials & Continua 2024年第6期79卷 5105-5124页

作者： Shuming Sha Naiwang Guo wang Luo yong Zhang Nanjing NARI Information&Communication Technology Co. Ltd.Nanjing210032China State Grid Electric Power Research Institute Nanjing211106China State Grid Shanghai Municipal Eleciric Power Company Shanghai200122China

This paper focuses on the scheduling problem of workflow tasks that exhibit *** indepen-dent batch tasks,workflows typically consist of multiple subtasks with intrinsic correlations and *** necessitates the distribution of various computational tasks to appropriate computing node resources in accor-dance with task dependencies to ensure the smooth completion of the entire *** scheduling must consider an array of factors,including task dependencies,availability of computational resources,and the schedulability of ***,this paper delves into the distributed graph database workflow task scheduling problem and proposes a workflow scheduling methodology based on deep reinforcement learning(DRL).The method optimizes the maximum completion time(makespan)and response time of workflow tasks,aiming to enhance the responsiveness of workflow tasks while ensuring the minimization of the *** experimental results indicate that the Q-learning Deep Reinforcement Learning(Q-DRL)algorithm markedly diminishes the makespan and refines the average response time within distributed graph database *** quantifying makespan,Q-DRL achieves mean reductions of 12.4%and 11.9%over established First-fit and Random scheduling strategies,***,Q-DRL surpasses the performance of both DRL-Cloud and Improved Deep Q-learning Network(IDQN)algorithms,with improvements standing at 4.4%and 2.6%,*** reference to average response time,the Q-DRL approach exhibits a significantly enhanced performance in the scheduling of workflow tasks,decreasing the average by 2.27%and 4.71%when compared to IDQN and DRL-Cloud,*** Q-DRL algorithm also demonstrates a notable increase in the efficiency of system resource utilization,reducing the average idle rate by 5.02%and 9.30%in comparison to IDQN and DRL-Cloud,*** findings support the assertion that Q-DRL not only upholds a lower average

关键词： Reinforcement learning workflow task scheduling load balancing

MOF-templated tubular Ni_(1−x)Co_(x)S_(2)-CdS heterojunction with intensified direct Z-scheme charge transmission for highly promoted visible-light photocatalysis

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Nano Research 2024年第7期17卷 6281-6293页

作者： chuan Jiang Yuanxin Qiu Xinxin Xin Yanyan Li Huilin Li Hui wang Jixiang Xu Haifeng Lin Lei wang Volodymyr Turkevych Key Laboratory of Eco-chemical Engineering International S&T Cooperation Foundation of Eco-chemical Engineering and Green ManufactureCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization Key Laboratory of Rubber-Plastics of Ministry of EducationSchool of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042China V.Bakul Institute for Superhard Materials National Academy of Sciences of UkraineKyiv 04074Ukraine

Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions,and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hinge to achieve excellent solar conversion *** this work,tubular Ni_(1−x)Co_(x)S_(2)-CdS heterostructures with reinforced Z-scheme charge transmission were constructed through an In-metal-organic framework(MOF)templated *** Z-scheme charge transfer mechanism was sufficiently confirmed by combining density functional theory(DFT)calculation,X-ray photoelectron spectroscopy(XPS),surface photovoltage spectroscopy(SPV),and radical testing ***,the use of sodium citrate complexant contributes to the formation of intimate heterointerface,and the Fermi level gap between CdS and NiS_(2)is enlarged through Co doping into NiS_(2),which enhances the built-in electric field and photo-carriers transmission driving force for Ni_(1−x)Co_(x)S_(2)-CdS heterojunction,resulting in an evidently promoted activity toward H2 evolution reaction(HER).Under visible-light(λ>400 nm)irradiation,the Ni_(1−x)Co_(x)S_(2)-CdS composite with 10 mol%Co doping and 80 wt.%CdS(NC_(0.10)S-80%CdS)achieved an outstanding HER rate up to 35.94 mmol·g^(−1)·h^(−1)(corresponding to the apparent quantum efficiency of 34.7%at 420 nm),approximately 76.4 times that of 3 wt.%Pt-loaded CdS and it is much superior to that of most CdS-based photocatalysts ever ***,the good photocatalytic durability of Ni_(1−x)Co_(x)S_(2)-CdS heterostructures was validated by cycling and long-term HER *** work could inspire the development of high-performance Z-scheme heterojunction via optimizing the morphology and interfacial charge transmission.

关键词： tubular heterostructure Z-scheme charge transmission interfacial coupling built-in electric field visible-light photocatalysis

Microstructure Recrystallization and Mechanical Properties of a Cold-Rolled TiNbZrTaHf Refractory High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 633-647页

作者： chuan Rong Jieren Yang Xiaoliang Zhao Ke Huang Ying Liu Xiaohong wang Dongdong Zhu Ruirun Chen College of Materials Science and Engineering Sichuan UniversityChengdu610065China Key Laboratory of Air-Driven Equipment Technology of Zhejiang Province Quzhou UniversityQuzhou324000China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

The equiatomic TiNbZrTaHf alloy was successfully rolled at room temperature with the reduction of ~ 85%. The microstructure and tensile properties were investigated after cold working and annealing. It was determined that the recrystallization temperature of the TiNbZrTaHf alloy between 850 and 900 ℃. Complete recrystallization and normal grain growth occurred, the high stability of single phase was maintained after annealing at 1000, 1200, and 1400 ℃. But the precipitated phase appeared after long term annealing, as seen after 500 h at 1000 ℃. After cold working, the tensile strength and the elongation of TiNbZrTaHf were 1137 MPa and 25.1%, respectively. The annealed alloy has a high tensile strength (σ_(b )= 863 MPa) and ductility (ε_(e )= 28.5%). Moreover, the oxidation of TiNbZrTaHf alloy at elevated temperatures has a significant impact on its mechanical properties. The poor oxidation resistance of TiNbZrTaHf can accelerate tensile failure by inducing fractures at grain boundaries.

关键词： Refractory high entropy alloy Cold rolling Recrystallization Oxidation resistance Mechanical properties

Trustworthy semi-supervised anomaly detection for online‐tooffline logistics business in merchant identification

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CAAI Transactions on Intelligence Technology 2024年第3期9卷 544-556页

作者： yong Li Shuhang wang Shijie Xu Jiao Yin Business School China University of Political Science and LawBeijingChina JD Logistics BeijingChina Southeast University NanjingChina Institute for Sustainable Industries and Liveable Cities Victoria UniversityMelbourneVictoriaAustralia

The rise of online-to-offline(O2O)e-commerce business has brought tremendous opportunities to the logistics *** the online-to-offline logistics business,it is essential to detect anomaly merchants with fraudulent shipping behaviours,such as sending other merchants'packages for profit with their low *** can help reduce the financial losses of platforms and ensure a healthy *** anomaly detection studies have mainly focused on online fraud behaviour detection,such as fraudulent purchase and comment behaviours in ***,these methods are not suitable for anomaly merchant detection in logistics due to the more complex online and offline operation of package-sending behaviours and the interpretable requirements of offline deployment in ***,a semi-supervised multiview fusion-based Anomaly Detection framework in online-to-offline logistics is proposed,which consists of a basic version SemiDet and an attention-enhanced multi-view fusion *** SemiDet,pair-wise data augmentation is first conducted to promote model robustness and address the challenge of limited labelled anomaly ***,SemiDet calculates the anomaly scoring of each merchant with an auto-encoder *** the multi-relationships among logistics merchants,a multi-view attention fusion-based anomaly detection network is further designed to capture merchants'mutual influences and improve the anomaly merchant detection performance.A post-hoc perturbation-based interpretation model is designed to output the importance of different views and ensure the trustworthiness of end-to-end anomaly *** framework based on an eight-month real-world dataset collected from one of the largest logistics platforms in China is evaluated,involving 6128 merchants and 16 million historical order consignor records in *** results show that the proposed model outperforms other baselines in both AUC-ROC and AUC-PR metrics.

关键词： artificial intelligence techniques data fusion deep learning